Slavery of people from Africa and East Asia was succeeded by the modern Kafala system of poor workers from the same region were slaves had previously been imported.
From Oman, the slaves were exported to the rest of the Arabian Peninsula and Persia, including the Trucial States, Qatar, Bahrain and Kuwait.
A second route of slave trade existed, with people from both Africa and East Asia, who were smuggled to Jeddah in the Arabian Peninsula in connection to the Muslim pilgrimage, Hajj, to Mecca and Medina.
Victims were tricked to perform the journey willingly in the belief that they were going on the Hajj pilgrimage, or employed as servants, and then sold upon arrival.
In the 1940s, a third slave trade route was noted, in which Balochis from Balochistan were shipped across the Persian Gulf, many of whom had sold themselves or their children to escape poverty.
[5] Non-African female slaves were sold in the Persian Gulf where they were bought for marriage; these were fewer and often Armenian, Georgian, or from Baluchistan and India.
[7] It was common for Arab men to use the sexual services of enslaved African women, but a male African slave who had sexual relations with a local "pure blood" Arab woman would be executed to preserve tribal honor and social status, regardless if the couple had married or not.
[13] In both 1932 and 1935, the British colonial authorities refused to interfere in the slavery of the Trucial States, Qatar, Bahrain and Kuwait, since they were afraid that they could lose control over the area if they should attempt to enforce a policy against slavery, and they therefore prevented all international observations of the area which could force them to take action.
[17] In reality, the British reports were deliberately playing down the size of the actual substantional slave trade going on in the region, and refused to allow international inspection.
The original law of kafala was expanded to include a system of fixed-term sponsorship of migrant workers in several countries in the late twentieth century.
[26] Changes to the Labour Market Regulatory Suggestion were made in April 2009 and implemented starting 1 August 2009.
[27] However, in November 2009 Human Rights Watch (HRW) stated that "authorities do little to enforce compliance" with "employers who withhold wages and passports from migrant employees ... practices [which] are illegal under Bahraini law.